Influenza is one of the major public health threats and NIH biodefense research priorities. Transmission of H5N1 influenza virus from the avian species to human shows great urgency for the development of an effective vaccine against influenza. The objective of this research is to develop an effective influenza vaccine using the relatively conserved matrix protein 2 (M2) of H5N1 avian influenza A virus as an antigen delivered by a detoxified anthrax edema toxin. Since the anthrax toxins are capable of entering host cells for antigen delivery through the major histocompatibility complex (MHC) class I and class II pathways, the proposed vaccine may elicit potent cell-mediated immunity against influenza antigens. We hypothesize that the proposed vaccine is able to cross-protect against H5N1 and other types of influenza A viruses. Importantly, the proposed vaccine could be administrated through a noninvasive nasal mucosal route which is convenient for administration and maybe more efficient to elicit mucosal immunity for protection against a possible pandemic influenza. In order to evaluate these hypotheses, we will evaluate the efficacy of intranasal delivery of the proposed vaccine in a mouse model. The specific aims of this project are: Specific Aim #1: To produce recombinant fusion N-fragment of anthrax edema factor with M2. Specific Aim #2: To study the systemic and mucosal immunity against influenza viruses after intranasal vaccination in mice with the fusion EFn/M2 in combination with the anthrax protective antigen. Specific Aim #3: To determine the efficacy of the proposed vaccine for protection against H5 and other influenza A virus strains in a mouse model. Specific Aim #4: To assess toxicity of the proposed vaccine in animals after vaccination. The success of the proposed research will provide not only a new and easily administered influenza vaccine but also a platform for development of mucosal vaccines against other infectious diseases. PUBLIC HEALTH RELEVANCE: Influenza is both a major public health threat and a NIAID biodefense research priority. Transmission of H5N1 influenza virus from the avian species to human shows great urgency for the development of an effective vaccine against influenza viruses. We propose to develop a vaccine which could be administrated through a noninvasive nasal mucosal route and maybe more efficient to elicit mucosal and systemic immunity for protection against a possible pandemic influenza. This will meet the urgent need for public health.